A153419 Primes p such that p+20 is also prime.

3, 11, 17, 23, 41, 47, 53, 59, 83, 89, 107, 131, 137, 173, 179, 191, 251, 257, 263, 293, 311, 317, 347, 353, 359, 389, 401, 419, 443, 467, 479, 503, 521, 557, 587, 593, 599, 641, 653, 719, 809, 839, 857, 863, 887, 947, 971, 977, 1013, 1019, 1031, 1049, 1097

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Dec 25 2008

Keywords

• nonn
• easy

Examples

			3 is in the sequence because 3+20=23 is prime; 11 is in the sequence because 11+20=31 is prime.
		

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..10000 (first 1000 terms from Vincenzo Librandi)

Crossrefs

Cf. A153417, A049488, A153418.

Programs

Magma

[p: p in PrimesUpTo(1100) | IsPrime(p + 20)]; // Vincenzo Librandi, Apr 14 2013

Maple

for a from 1 to 140 do if isprime(a) and isprime(a+20) then print(a)
  end if;  end do; # Matt C. Anderson, Jun 20 2022

Mathematica

Select[Prime[Range[200]], PrimeQ[(# + 20)]&] (* Vincenzo Librandi, Apr 14 2013 *)

Extensions

Definition improved from Bruno Berselli, Oct 31 2012